Applicants claim priority under 35 U.S.C. xc2xa7119 of German Application No. 199 59 490.2 filed Dec. 10, 1999. Applicants also claim priority under 35 U.S.C. xc2xa7120 of PCT/EP00/12251 filed Dec. 6, 2000. The international application under PCT article 21(2) was not published in English.
The invention relates to a drum for electropolishing bulk metal parts, in particular stainless steel parts.
Known and commercially available is a drum for electropolishing bulk stain steel parts that rotates with current-conducting support arms in an electrolyte bath. The cathode is formed in this connection by a tube that is centrally and coaxially arranged in the interior of the drum. The anode is formed by the jacket of the drum. For the electropolishing operation, the bulk stain steel parts are filled in said drum only to such a degree of filling at which it is assured that the stain steel parts to be polished will not come into contact with the cathode, because that would otherwise cause disruptive discharges and burning of the parts to be treated, which has to be avoided. Therefore, only small amounts of bulk stain steel parts can be accordingly treated in such drums.
Due to the currents passed through the electrolytes, charge transports of ions are achieved in connection with such an electropolishing process. Surface portions are removed in the processes for electropolishing accordingly, and moved to the cathode.
A device for the electrolytic polishing particularly of small metal parts is known already from DE 2 009 189 A1, in which a tubular anode is concentrically arranged in the receiving drum. Provision is made on said tube on the end sides for flaps, which are spaced from each other and have stepped diameters in accordance with the shape of the drum. Only a low degree of filling can be achieved with such a drum as well.
The problem of the invention is to propose a drum of the type specified above, in which greater amounts of bulk stain steel parts, in particular small parts can be treated.
The problem of the invention is solved with a drum having the features of claim 1. A preferred type of embodiment of the invention is specified in claim 2.
By arranging a ring-shaped drum forming the anode and receiving the metal parts, in particular the stainless steel parts, with a spacing from the jacket of the actual drum, it is assured that the stainless steel parts to be treated cannot come into contact with the centrally arranged cathode. Taking into account the clear space required between the two drums, it is possible in this way to obtain space for receiving and treating the stainless""steel parts. With respect to the diameter and the size of the actual drum, such space can receive a substantially larger proportion of the volume than the filling space within the known drums of this type available until now. Drums of the type as defined by the invention are therefore by far more effective than the known drums of said type.
Preferably employed construction variations and elements are specified in the dependent claims and explained in greater detail in the following.